remix-project/src/universal-dapp.js

/* global prompt */
'use strict'

var $ = require('jquery')
var ethJSUtil = require('ethereumjs-util')
var EthJSTX = require('ethereumjs-tx')
var ethJSABI = require('ethereumjs-abi')
var EthJSBlock = require('ethereumjs-block')
var BN = ethJSUtil.BN
var EventManager = require('./lib/eventManager')
var crypto = require('crypto')
var async = require('async')

/*
  trigger debugRequested
*/
function UniversalDApp (executionContext, options, txdebugger) {
  this.event = new EventManager()
  var self = this

  self.options = options || {}
  self.$el = $('<div class="udapp" />')
  self.personalMode = self.options.personalMode || false
  self.contracts
  self.getAddress
  self.getValue
  self.getGasLimit
  self.txdebugger = txdebugger // temporary: will not be needed anymore when we'll add memory support to the VM
  var defaultRenderOutputModifier = function (name, content) { return content }
  self.renderOutputModifier = defaultRenderOutputModifier
  self.web3 = executionContext.web3()
  self.vm = executionContext.vm()
  self.executionContext = executionContext
  self.executionContext.event.register('contextChanged', this, function (context) {
    self.reset(self.contracts)
  })
}

UniversalDApp.prototype.reset = function (contracts, getAddress, getValue, getGasLimit, renderer) {
  this.$el.empty()
  this.contracts = contracts
  this.getAddress = getAddress
  this.getValue = getValue
  this.getGasLimit = getGasLimit
  this.renderOutputModifier = renderer
  this.accounts = {}
  if (this.executionContext.isVM()) {
    this._addAccount('3cd7232cd6f3fc66a57a6bedc1a8ed6c228fff0a327e169c2bcc5e869ed49511')
    this._addAccount('2ac6c190b09897cd8987869cc7b918cfea07ee82038d492abce033c75c1b1d0c')
    this._addAccount('dae9801649ba2d95a21e688b56f77905e5667c44ce868ec83f82e838712a2c7a')
    this._addAccount('d74aa6d18aa79a05f3473dd030a97d3305737cbc8337d940344345c1f6b72eea')
    this._addAccount('71975fbf7fe448e004ac7ae54cad0a383c3906055a65468714156a07385e96ce')
    this.blockNumber = 1150000 // The VM is running in Homestead mode, which started at this block.
  }
}

UniversalDApp.prototype.newAccount = function (password) {
  if (!this.executionContext.isVM()) {
    if (!this.personalMode) {
      throw new Error('Not running in personal mode')
    }
    this.web3.personal.newAccount(password)
  } else {
    var privateKey
    do {
      privateKey = crypto.randomBytes(32)
    } while (!ethJSUtil.isValidPrivate(privateKey))
    this._addAccount(privateKey)
  }
}

UniversalDApp.prototype._addAccount = function (privateKey, balance) {
  var self = this

  if (!self.executionContext.isVM()) {
    throw new Error('_addAccount() cannot be called in non-VM mode')
  }

  if (self.accounts) {
    privateKey = new Buffer(privateKey, 'hex')
    var address = ethJSUtil.privateToAddress(privateKey)

    // FIXME: we don't care about the callback, but we should still make this proper
    self.vm.stateManager.putAccountBalance(address, balance || 'f00000000000000001', function cb () {})

    self.accounts['0x' + address.toString('hex')] = { privateKey: privateKey, nonce: 0 }
  }
}

UniversalDApp.prototype.getAccounts = function (cb) {
  var self = this

  if (!self.executionContext.isVM()) {
    // Weirdness of web3: listAccounts() is sync, `getListAccounts()` is async
    // See: https://github.com/ethereum/web3.js/issues/442
    if (self.personalMode) {
      self.web3.personal.getListAccounts(cb)
    } else {
      self.web3.eth.getAccounts(cb)
    }
  } else {
    if (!self.accounts) {
      return cb('No accounts?')
    }

    cb(null, Object.keys(self.accounts))
  }
}

UniversalDApp.prototype.getBalance = function (address, cb) {
  var self = this

  address = ethJSUtil.stripHexPrefix(address)

  if (!self.executionContext.isVM()) {
    self.web3.eth.getBalance(address, function (err, res) {
      if (err) {
        cb(err)
      } else {
        cb(null, res.toString(10))
      }
    })
  } else {
    if (!self.accounts) {
      return cb('No accounts?')
    }

    self.vm.stateManager.getAccountBalance(new Buffer(address, 'hex'), function (err, res) {
      if (err) {
        cb('Account not found')
      } else {
        cb(null, new BN(res).toString(10))
      }
    })
  }
}

UniversalDApp.prototype.render = function () {
  var self = this

  // NOTE: don't display anything if there are no contracts to display
  if (self.contracts.length === 0) {
    return self.$el
  }

  var $legend = $('<div class="legend" />')
    .append($('<div class="attach"/>').text('Attach'))
    .append($('<div class="transact"/>').text('Transact'))
    .append($('<div class="call"/>').text('Call'))

  self.$el.append($legend)

  for (var c in self.contracts) {
    var $contractEl = $('<div class="contract"/>')

    if (self.contracts[c].address) {
      self.getInstanceInterface(self.contracts[c], self.contracts[c].address, $contractEl)
    } else {
      var $title = $('<span class="title"/>').text(self.contracts[c].name)
      if (self.contracts[c].bytecode) {
        $title.append($('<div class="size"/>').text((self.contracts[c].bytecode.length / 2) + ' bytes'))
      }
      $contractEl.append($title).append(self.getCreateInterface($contractEl, self.contracts[c]))
    }
    self.$el.append(self.renderOutputModifier(self.contracts[c].name, $contractEl))
  }

  return self.$el
}

UniversalDApp.prototype.getContractByName = function (contractName) {
  var self = this
  for (var c in self.contracts) {
    if (self.contracts[c].name === contractName) {
      return self.contracts[c]
    }
  }
  return null
}

UniversalDApp.prototype.getCreateInterface = function ($container, contract) {
  var self = this
  var $createInterface = $('<div class="create"/>')
  if (self.options.removable) {
    var $close = $('<div class="udapp-close" />')
    $close.click(function () { self.$el.remove() })
    $createInterface.append($close)
  }
  var $atButton = $('<button class="atAddress"/>').text('At Address').click(function () { self.clickContractAt(self, $container.find('.createContract'), contract) })
  $createInterface.append($atButton)

  var $newButton = self.getInstanceInterface(contract)
  $createInterface.append($newButton)

  // Only display creation interface for non-abstract contracts.
  // FIXME: maybe have a flag for this in the JSON?
  // FIXME: maybe fix getInstanceInterface() below for this case
  if (contract.bytecode.length === 0) {
    var $createButton = $newButton.find('.constructor .call')

    // NOTE: we must show the button to have CSS properly lined up
    $createButton.text('Create')
    $createButton.attr('disabled', 'disabled')
    $createButton.attr('title', 'This contract does not implement all functions and thus cannot be created.')
  }

  return $createInterface
}

UniversalDApp.prototype.getInstanceInterface = function (contract, address, $target) {
  var self = this
  var abi = JSON.parse(contract.interface).sort(function (a, b) {
    if (a.name > b.name) {
      return -1
    } else {
      return 1
    }
  }).sort(function (a, b) {
    if (a.constant === true) {
      return -1
    } else {
      return 1
    }
  })
  var funABI = self.getConstructorInterface(abi)
  var $createInterface = $('<div class="createContract"/>')

  var appendFunctions = function (address, $el) {
    var $instance = $('<div class="instance"/>')
    if (self.options.removable_instances) {
      var $close = $('<div class="udapp-close" />')
      $close.click(function () { $instance.remove() })
      $instance.append($close)
    }
    var context = self.executionContext.isVM() ? 'memory' : 'blockchain'

    address = (address.slice(0, 2) === '0x' ? '' : '0x') + address.toString('hex')
    var $title = $('<span class="title"/>').text(contract.name + ' at ' + address + ' (' + context + ')')
    $title.click(function () {
      $instance.toggleClass('hide')
    })

    var $events = $('<div class="events"/>')

    var parseLogs = function (err, response) {
      if (err) {
        return
      }

      var $event = $('<div class="event" />')

      var $close = $('<div class="udapp-close" />')
      $close.click(function () { $event.remove() })

      $event.append($('<span class="name"/>').text(response.event))
        .append($('<span class="args" />').text(JSON.stringify(response.args, null, 2)))
        .append($close)

      $events.append($event)
    }

    if (self.executionContext.isVM()) {
      // FIXME: support indexed events
      var eventABI = {}

      $.each(abi, function (i, funABI) {
        if (funABI.type !== 'event') {
          return
        }

        var hash = ethJSABI.eventID(funABI.name, funABI.inputs.map(function (item) { return item.type }))
        eventABI[hash.toString('hex')] = { event: funABI.name, inputs: funABI.inputs }
      })

      self.vm.on('afterTx', function (response) {
        for (var i in response.vm.logs) {
          // [address, topics, mem]
          var log = response.vm.logs[i]
          var event
          var decoded

          try {
            var abi = eventABI[log[1][0].toString('hex')]
            event = abi.event
            var types = abi.inputs.map(function (item) {
              return item.type
            })
            decoded = ethJSABI.rawDecode(types, log[2])
            decoded = ethJSABI.stringify(types, decoded)
          } catch (e) {
            decoded = '0x' + log[2].toString('hex')
          }

          parseLogs(null, { event: event, args: decoded })
        }
      })
    } else {
      var eventFilter = self.web3.eth.contract(abi).at(address).allEvents()
      eventFilter.watch(parseLogs)
    }
    $instance.append($title)

    // Add the fallback function
    $instance.append(self.getCallButton({
      abi: { constant: false, inputs: [], name: '(fallback)', outputs: [], type: 'function' },
      encode: function (args) {
        return ''
      },
      address: address
    }))

    $.each(abi, function (i, funABI) {
      if (funABI.type !== 'function') {
        return
      }
      // @todo getData cannot be used with overloaded functions
      $instance.append(self.getCallButton({
        abi: funABI,
        encode: function (args) {
          var types = []
          for (var i = 0; i < funABI.inputs.length; i++) {
            types.push(funABI.inputs[i].type)
          }

          return Buffer.concat([ ethJSABI.methodID(funABI.name, types), ethJSABI.rawEncode(types, args) ]).toString('hex')
        },
        address: address
      }))
    })

    $el = $el || $createInterface
    $el.append($instance.append($events))
  }

  if (!address || !$target) {
    $createInterface.append(self.getCallButton({
      abi: funABI,
      encode: function (args) {
        var types = []
        for (var i = 0; i < funABI.inputs.length; i++) {
          types.push(funABI.inputs[i].type)
        }

        // NOTE: the caller will concatenate the bytecode and this
        //       it could be done here too for consistency
        return ethJSABI.rawEncode(types, args).toString('hex')
      },
      contractName: contract.name,
      bytecode: contract.bytecode,
      appendFunctions: appendFunctions
    }))
  } else {
    appendFunctions(address, $target)
  }

  return $createInterface
}

// either return the supplied constructor or a mockup (we assume everything can be instantiated)
UniversalDApp.prototype.getConstructorInterface = function (abi) {
  var funABI = { 'name': '', 'inputs': [], 'type': 'constructor', 'outputs': [] }
  for (var i = 0; i < abi.length; i++) {
    if (abi[i].type === 'constructor') {
      funABI.inputs = abi[i].inputs || []
      break
    }
  }
  return funABI
}

UniversalDApp.prototype.getCallButton = function (args) {
  var self = this
  // args.abi, args.encode, args.bytecode [constr only], args.address [fun only]
  // args.contractName [constr only], args.appendFunctions [constr only]
  var isConstructor = args.bytecode !== undefined
  var lookupOnly = (args.abi.constant && !isConstructor)

  var inputs = ''
  $.each(args.abi.inputs, function (i, inp) {
    if (inputs !== '') {
      inputs += ', '
    }
    inputs += inp.type + ' ' + inp.name
  })
  var inputField = $('<input/>').attr('placeholder', inputs).attr('title', inputs)
  var $outputOverride = $('<div class="value" />')
  var outputSpan = $('<div class="output"/>')

  var getReturnOutput = function (result) {
    var returnName = lookupOnly ? 'Value' : 'Result'
    var returnCls = lookupOnly ? 'value' : 'returned'
    return $('<div class="' + returnCls + '">').html('<strong>' + returnName + ':</strong> ' + JSON.stringify(result, null, 2))
  }

  var getDebugTransaction = function (result) {
    var $debugTx = $('<div class="debugTx">')
    var $button = $('<button title="Launch Debugger" class="debug"><i class="fa fa-bug"></i></button>')
    $button.click(function () {
      self.event.trigger('debugRequested', [result])
    })
    $debugTx.append($button)
    return $debugTx
  }

  var getDebugCall = function (result) {
    var $debugTx = $('<div class="debugCall">')
    var $button = $('<button title="Launch Debugger" class="debug"><i class="fa fa-bug"></i></button>')
    $button.click(function () {
      self.event.trigger('debugRequested', [result])
    })
    $debugTx.append($button)
    return $debugTx
  }

  var getGasUsedOutput = function (result, vmResult) {
    var $gasUsed = $('<div class="gasUsed">')
    var caveat = lookupOnly ? '<em>(<span class="caveat" title="Cost only applies when called by a contract">caveat</span>)</em>' : ''
    var gas
    if (result.gasUsed) {
      gas = result.gasUsed.toString(10)
      $gasUsed.html('<strong>Transaction cost:</strong> ' + gas + ' gas. ' + caveat)
    }
    if (vmResult && vmResult.gasUsed) {
      var $callGasUsed = $('<div class="gasUsed">')
      gas = vmResult.gasUsed.toString(10)
      $callGasUsed.append('<strong>Execution cost:</strong> ' + gas + ' gas.')
      $gasUsed.append($callGasUsed)
    }
    return $gasUsed
  }

  var getDecodedOutput = function (result) {
    var $decoded
    if (Array.isArray(result)) {
      $decoded = $('<ol>')
      for (var i = 0; i < result.length; i++) {
        $decoded.append($('<li>').text(result[i]))
      }
    } else {
      $decoded = result
    }
    return $('<div class="decoded">').html('<strong>Decoded:</strong> ').append($decoded)
  }

  var getOutput = function () {
    var $result = $('<div class="result" />')
    var $close = $('<div class="udapp-close" />')
    $close.click(function () { $result.remove() })
    $result.append($close)
    return $result
  }
  var clearOutput = function ($result) {
    $(':not(.udapp-close)', $result).remove()
  }
  var replaceOutput = function ($result, message) {
    clearOutput($result)
    $result.append(message)
  }

  var handleCallButtonClick = function (ev, $result) {
    if (!$result) {
      $result = getOutput()
      if (lookupOnly && !inputs.length) {
        $outputOverride.empty().append($result)
      } else {
        outputSpan.append($result)
      }
    }

    var funArgs = ''
    try {
      funArgs = $.parseJSON('[' + inputField.val() + ']')
    } catch (e) {
      replaceOutput($result, $('<span/>').text('Error encoding arguments: ' + e))
      return
    }
    var data = ''
    if (!isConstructor || funArgs.length > 0) {
      try {
        data = args.encode(funArgs)
      } catch (e) {
        replaceOutput($result, $('<span/>').text('Error encoding arguments: ' + e))
        return
      }
    }
    if (data.slice(0, 9) === 'undefined') {
      data = data.slice(9)
    }
    if (data.slice(0, 2) === '0x') {
      data = data.slice(2)
    }

    replaceOutput($result, $('<span>Waiting for transaction to be mined...</span>'))

    if (isConstructor) {
      if (args.bytecode.indexOf('_') >= 0) {
        replaceOutput($result, $('<span>Deploying and linking required libraries...</span>'))
        self.linkBytecode(args.contractName, function (err, bytecode) {
          if (err) {
            replaceOutput($result, $('<span/>').text('Error deploying required libraries: ' + err))
          } else {
            args.bytecode = bytecode
            handleCallButtonClick(ev, $result)
          }
        })
        return
      } else {
        data = args.bytecode + data
      }
    }

    var decodeResponse = function (response) {
      // Only decode if there supposed to be fields
      if (args.abi.outputs.length > 0) {
        try {
          var i

          var outputTypes = []
          for (i = 0; i < args.abi.outputs.length; i++) {
            outputTypes.push(args.abi.outputs[i].type)
          }

          // decode data
          var decodedObj = ethJSABI.rawDecode(outputTypes, response)

          // format decoded data
          decodedObj = ethJSABI.stringify(outputTypes, decodedObj)
          for (i = 0; i < outputTypes.length; i++) {
            var name = args.abi.outputs[i].name
            if (name.length > 0) {
              decodedObj[i] = outputTypes[i] + ' ' + name + ': ' + decodedObj[i]
            } else {
              decodedObj[i] = outputTypes[i] + ': ' + decodedObj[i]
            }
          }

          return getDecodedOutput(decodedObj)
        } catch (e) {
          return getDecodedOutput('Failed to decode output: ' + e)
        }
      }
    }

    var decoded
    self.runTx({ to: args.address, data: data, useCall: args.abi.constant && !isConstructor }, function (err, result) {
      if (err) {
        replaceOutput($result, $('<span/>').text(err).addClass('error'))
      // VM only
      } else if (self.executionContext.isVM() && result.vm.exception === 0 && result.vm.exceptionError) {
        replaceOutput($result, $('<span/>').text('VM Exception: ' + result.vm.exceptionError).addClass('error'))
        $result.append(getDebugTransaction(result))
      // VM only
      } else if (self.executionContext.isVM() && result.vm.return === undefined) {
        replaceOutput($result, $('<span/>').text('Exception during execution.').addClass('error'))
        $result.append(getDebugTransaction(result))
      } else if (isConstructor) {
        replaceOutput($result, getGasUsedOutput(result, result.vm))
        $result.append(getDebugTransaction(result))
        args.appendFunctions(self.executionContext.isVM() ? result.createdAddress : result.contractAddress)
      } else if (self.executionContext.isVM()) {
        var outputObj = '0x' + result.vm.return.toString('hex')
        clearOutput($result)
        $result.append(getReturnOutput(outputObj)).append(getGasUsedOutput(result, result.vm))

        decoded = decodeResponse(result.vm.return)
        if (decoded) {
          $result.append(decoded)
        }
        if (args.abi.constant) {
          $result.append(getDebugCall(result))
        } else {
          $result.append(getDebugTransaction(result))
        }
      } else if (args.abi.constant && !isConstructor) {
        clearOutput($result)
        $result.append(getReturnOutput(result)).append(getGasUsedOutput({}))

        decoded = decodeResponse(ethJSUtil.toBuffer(result))
        if (decoded) {
          $result.append(decoded)
        }
      } else {
        clearOutput($result)
        $result.append(getReturnOutput(result)).append(getGasUsedOutput(result))
        $result.append(getDebugTransaction(result))
      }
    })
  }

  var button = $('<button />')
    .addClass('call')
    .attr('title', args.abi.name)
    .text(args.bytecode ? 'Create' : args.abi.name)
    .click(handleCallButtonClick)

  if (lookupOnly && !inputs.length) {
    handleCallButtonClick()
  }

  var $contractProperty = $('<div class="contractProperty"/>')
  $contractProperty
    .toggleClass('constant', !isConstructor && args.abi.constant)
    .toggleClass('hasArgs', args.abi.inputs.length > 0)
    .toggleClass('constructor', isConstructor)
    .append(button)
    .append((lookupOnly && !inputs.length) ? $outputOverride : inputField)
  return $contractProperty.append(outputSpan)
}

UniversalDApp.prototype.linkBytecode = function (contractName, cb) {
  var self = this
  var bytecode = self.getContractByName(contractName).bytecode
  if (bytecode.indexOf('_') < 0) {
    return cb(null, bytecode)
  }
  var m = bytecode.match(/__([^_]{1,36})__/)
  if (!m) {
    return cb('Invalid bytecode format.')
  }
  var libraryName = m[1]
  if (!self.getContractByName(libraryName)) {
    return cb('Library ' + libraryName + ' not found.')
  }
  self.deployLibrary(libraryName, function (err, address) {
    if (err) {
      return cb(err)
    }
    var libLabel = '__' + libraryName + Array(39 - libraryName.length).join('_')
    var hexAddress = address.toString('hex')
    if (hexAddress.slice(0, 2) === '0x') {
      hexAddress = hexAddress.slice(2)
    }
    hexAddress = Array(40 - hexAddress.length + 1).join('0') + hexAddress
    while (bytecode.indexOf(libLabel) >= 0) {
      bytecode = bytecode.replace(libLabel, hexAddress)
    }
    self.getContractByName(contractName).bytecode = bytecode
    self.linkBytecode(contractName, cb)
  })
}

UniversalDApp.prototype.deployLibrary = function (contractName, cb) {
  var self = this
  if (self.getContractByName(contractName).address) {
    return cb(null, self.getContractByName(contractName).address)
  }
  var bytecode = self.getContractByName(contractName).bytecode
  if (bytecode.indexOf('_') >= 0) {
    self.linkBytecode(contractName, function (err, bytecode) {
      if (err) cb(err)
      else self.deployLibrary(contractName, cb)
    })
  } else {
    self.runTx({ data: bytecode, useCall: false }, function (err, result) {
      if (err) {
        return cb(err)
      }
      var address = self.executionContext.isVM() ? result.createdAddress : result.contractAddress
      self.getContractByName(contractName).address = address
      cb(err, address)
    })
  }
}

UniversalDApp.prototype.clickContractAt = function (self, $output, contract) {
  var address = prompt('What Address is this contract at in the Blockchain? ie: 0xdeadbeaf...')
  self.getInstanceInterface(contract, address, $output)
}

function tryTillResponse (web3, txhash, done) {
  web3.eth.getTransactionReceipt(txhash, function (err, address) {
    if (!err && !address) {
      // Try again with a bit of delay
      setTimeout(function () { tryTillResponse(web3, txhash, done) }, 500)
    } else {
      done(err, address)
    }
  })
}

UniversalDApp.prototype.runTx = function (args, cb) {
  var self = this
  var tx = {
    to: args.to,
    data: args.data
  }

  async.waterfall([
    // query gas limit
    function (callback) {
      tx.gasLimit = 3000000

      // NOTE: getGasLimit should be async
      if (self.getGasLimit) {
        try {
          tx.gasLimit = self.getGasLimit()
          callback()
        } catch (e) {
          callback(e)
        }
      } else {
        callback()
      }
    },
    // query value
    function (callback) {
      tx.value = 0

      // NOTE: getValue should be async
      if (self.getValue) {
        try {
          tx.value = self.getValue()
          callback()
        } catch (e) {
          callback(e)
        }
      } else {
        callback()
      }
    },
    // query address
    function (callback) {
      // NOTE: getAddress should be async
      if (self.getAddress) {
        tx.from = self.getAddress()
        callback()
      } else {
        self.getAccounts(function (err, ret) {
          if (err) {
            return callback(err)
          }

          if (ret.length === 0) {
            return callback('No accounts available')
          }

          tx.from = ret[0]
          callback()
        })
      }
    },
    // run transaction
    function (callback) {
      self.rawRunTx(tx, callback)
    }
  ], cb)
}

UniversalDApp.prototype.rawRunTx = function (args, cb) {
  var self = this
  var from = args.from
  var to = args.to
  var data = args.data
  if (data.slice(0, 2) !== '0x') {
    data = '0x' + data
  }
  var value = args.value
  var gasLimit = args.gasLimit

  var tx
  if (!self.executionContext.isVM()) {
    tx = {
      from: from,
      to: to,
      data: data,
      value: value
    }
    if (args.useCall) {
      tx.gas = gasLimit
      self.web3.eth.call(tx, cb)
    } else {
      self.web3.eth.estimateGas(tx, function (err, resp) {
        if (err) {
          return cb(err, resp)
        }

        if (resp > gasLimit) {
          return cb('Gas required exceeds limit: ' + resp)
        }

        tx.gas = resp

        var sendTransaction = self.personalMode ? self.web3.personal.unlockAccountAndSendTransaction : self.web3.eth.sendTransaction

        sendTransaction(tx, function (err, resp) {
          if (err) {
            return cb(err, resp)
          }

          tryTillResponse(self.web3, resp, cb)
        })
      })
    }
  } else {
    try {
      var account = self.accounts[from]
      if (!account) {
        return cb('Invalid account selected')
      }
      tx = new EthJSTX({
        nonce: new BN(account.nonce++),
        gasPrice: new BN(1),
        gasLimit: new BN(gasLimit, 10),
        to: to,
        value: new BN(value, 10),
        data: new Buffer(data.slice(2), 'hex')
      })
      tx.sign(account.privateKey)
      var block = new EthJSBlock({
        header: {
          // FIXME: support coinbase, difficulty and gasLimit
          timestamp: new Date().getTime() / 1000 | 0,
          number: self.blockNumber
        },
        transactions: [],
        uncleHeaders: []
      })
      if (!args.useCall) {
        ++self.blockNumber
      }
      self.vm.runTx({block: block, tx: tx, skipBalance: true, skipNonce: true}, function (err, result) {
        result.transactionHash = self.txdebugger.web3().releaseCurrentHash() // used to keep track of the transaction
        cb(err, result)
      })
    } catch (e) {
      cb(e, null)
    }
  }
}

module.exports = UniversalDApp